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[apple/security.git] / OSX / sec / ProjectHeaders / Security / SecureObjectSync / SOSChangeTracker.c
diff --git a/OSX/sec/ProjectHeaders/Security/SecureObjectSync/SOSChangeTracker.c b/OSX/sec/ProjectHeaders/Security/SecureObjectSync/SOSChangeTracker.c
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+/*
+ * Copyright (c) 2015 Apple Inc. All Rights Reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+/*
+ * SOSChangeTracker.c -  Implementation of a manifest caching change tracker that forwards changes to children
+ */
+
+#include <Security/SecureObjectSync/SOSChangeTracker.h>
+#include <Security/SecureObjectSync/SOSDigestVector.h>
+#include <Security/SecureObjectSync/SOSEngine.h>
+#include <Security/SecureObjectSync/SOSManifest.h>
+#include <Security/SecureObjectSync/SOSInternal.h>
+#include <utilities/SecCFError.h>
+#include <utilities/SecCFWrappers.h>
+
+CFStringRef SOSChangeCopyDescription(SOSChangeRef change) {
+    CFTypeRef object = NULL;
+    bool isAdd = SOSChangeGetObject(change, &object);
+    // TODO: Print objects or digests
+    return (isData(object)
+            ? isAdd ? CFSTR("a") : CFSTR("d")
+            : isAdd ? CFSTR("A") : CFSTR("D"));
+}
+
+CFDataRef SOSChangeCopyDigest(SOSDataSourceRef dataSource, SOSChangeRef change, bool *isDel, SOSObjectRef *object, CFErrorRef *error) {
+    CFDataRef digest = NULL;
+    if (isArray(change)) {
+        if (CFArrayGetCount(change) != 1) {
+            SecError(errSecDecode, error, CFSTR("change array count: %ld"), CFArrayGetCount(change));
+            return NULL;
+        }
+        change = CFArrayGetValueAtIndex(change, 0);
+        *isDel = true;
+    } else {
+        *isDel = false;
+    }
+
+    // If the change is a CFData, this is the signal that it is a delete
+    if (isData(change)) {
+        digest = (CFDataRef)CFRetain(change);
+    } else {
+        digest = SOSObjectCopyDigest(dataSource, (SOSObjectRef)change, error);
+        *object = (SOSObjectRef)change;
+    }
+    assert(digest && CFDataGetLength(digest) == CCSHA1_OUTPUT_SIZE);
+    return digest;
+}
+
+CFStringRef SOSChangesCopyDescription(CFArrayRef changes) {
+    CFMutableStringRef desc = CFStringCreateMutableCopy(kCFAllocatorDefault, 0, CFSTR("("));
+    CFTypeRef change;
+    if (changes) CFArrayForEachC(changes, change) {
+        CFStringRef changeDesc = SOSChangeCopyDescription(change);
+        CFStringAppend(desc, changeDesc);
+        CFRetainSafe(changeDesc);
+    }
+    CFStringAppend(desc, CFSTR(")"));
+    return desc;
+}
+
+
+/* SOSChangeTracker implementation. */
+struct __OpaqueSOSChangeTracker {
+    CFRuntimeBase _base;
+    SOSManifestRef manifest;                // Optional: Only concrete cts have a manifest
+    CFMutableArrayRef changeChildren;       // Optional: cts can have children
+    CFMutableArrayRef manifestChildren;     // Optional: cts can have children
+};
+
+static CFStringRef SOSChangeTrackerCopyFormatDescription(CFTypeRef cf, CFDictionaryRef formatOptions) {
+    SOSChangeTrackerRef ct = (SOSChangeTrackerRef)cf;
+    CFStringRef desc = CFStringCreateWithFormat(kCFAllocatorDefault, formatOptions, CFSTR("<ChangeTracker %@ children %ld/%ld>"),
+                                                ct->manifest ? ct->manifest : (SOSManifestRef)CFSTR("NonConcrete"),
+                                                CFArrayGetCount(ct->changeChildren), CFArrayGetCount(ct->manifestChildren));
+    return desc;
+}
+
+static void SOSChangeTrackerDestroy(CFTypeRef cf) {
+    SOSChangeTrackerRef ct = (SOSChangeTrackerRef)cf;
+    CFReleaseSafe(ct->manifest);
+    CFReleaseSafe(ct->changeChildren);
+    CFReleaseSafe(ct->manifestChildren);
+}
+
+// Even though SOSChangeTracker instances are used as keys in dictionaries, they are treated as pointers when used as such
+// which is fine since the engine ensures instances are singletons.
+CFGiblisFor(SOSChangeTracker);
+
+SOSChangeTrackerRef SOSChangeTrackerCreate(CFAllocatorRef allocator, bool isConcrete, CFArrayRef changeChildren, CFErrorRef *error) {
+    SOSChangeTrackerRef ct = NULL;
+    ct = CFTypeAllocate(SOSChangeTracker, struct __OpaqueSOSChangeTracker, allocator);
+    if (ct && isConcrete) {
+        ct->manifest = SOSManifestCreateWithData(NULL, error);
+        if (!ct->manifest)
+            CFReleaseNull(ct);
+    }
+    if (ct) {
+        if (changeChildren)
+            ct->changeChildren = CFArrayCreateMutableCopy(kCFAllocatorDefault, 0, changeChildren);
+        else
+            ct->changeChildren = CFArrayCreateMutableForCFTypes(kCFAllocatorDefault);
+        ct->manifestChildren = CFArrayCreateMutableForCFTypes(kCFAllocatorDefault);
+    }
+
+    return ct;
+}
+
+// Change the concreteness of the current ct (a non concrete ct does not support SOSChangeTrackerCopyManifest().
+void SOSChangeTrackerSetConcrete(SOSChangeTrackerRef ct, bool isConcrete) {
+    if (!isConcrete)
+        CFReleaseNull(ct->manifest);
+    else if (!ct->manifest) {
+        ct->manifest = SOSManifestCreateWithData(NULL, NULL);
+    }
+}
+
+// Add a child to the current ct
+void SOSChangeTrackerRegisterChangeUpdate(SOSChangeTrackerRef ct, SOSChangeTrackerUpdatesChanges child) {
+    CFArrayAppendValue(ct->changeChildren, child);
+}
+
+void SOSChangeTrackerRegisterManifestUpdate(SOSChangeTrackerRef ct, SOSChangeTrackerUpdatesManifests child) {
+    CFArrayAppendValue(ct->manifestChildren, child);
+}
+
+void SOSChangeTrackerResetRegistration(SOSChangeTrackerRef ct) {
+    CFArrayRemoveAllValues(ct->changeChildren);
+    CFArrayRemoveAllValues(ct->manifestChildren);
+}
+
+void SOSChangeTrackerSetManifest(SOSChangeTrackerRef ct, SOSManifestRef manifest) {
+    CFRetainAssign(ct->manifest, manifest);
+}
+
+SOSManifestRef SOSChangeTrackerCopyManifest(SOSChangeTrackerRef ct, CFErrorRef *error) {
+    if (ct->manifest) {
+        return (SOSManifestRef)CFRetain(ct->manifest);
+    }
+    SOSErrorCreate(kSOSErrorNotConcreteError, error, NULL, CFSTR("ChangeTracker is not concrete"));
+    return NULL;
+}
+
+static bool SOSChangeTrackerCreateManifestsWithChanges(SOSEngineRef engine, CFArrayRef changes, SOSManifestRef *removals, SOSManifestRef *additions, CFErrorRef *error) {
+    bool ok = true;
+    struct SOSDigestVector dvdels = SOSDigestVectorInit;
+    struct SOSDigestVector dvadds = SOSDigestVectorInit;
+    struct SOSDigestVector *dv;
+    CFTypeRef change;
+    CFArrayForEachC(changes, change) {
+        CFDataRef digest, allocatedDigest = NULL;
+        if (isArray(change)) {
+            assert(CFArrayGetCount(change) == 1);
+            change = CFArrayGetValueAtIndex(change, 0);
+            dv = &dvdels;
+        } else {
+            dv = &dvadds;
+        }
+
+        if (isData(change)) {
+            digest = (CFDataRef)change;
+        } else {
+            CFErrorRef digestError = NULL;
+            digest = allocatedDigest = SOSObjectCopyDigest(SOSEngineGetDataSource(engine), (SOSObjectRef)change, &digestError);
+            if (!digest) {
+                secerror("change %@ SOSObjectCopyDigest: %@", change, digestError);
+                CFReleaseNull(digestError);
+                continue;
+            }
+        }
+
+        if (CFDataGetLength(digest) == 20) {
+            SOSDigestVectorAppend(dv, CFDataGetBytePtr(digest));
+        } else {
+            secerror("change %@ bad length digest: %@", change, digest);
+        }
+        CFReleaseNull(allocatedDigest);
+    }
+    if (ok && removals)
+        ok = *removals = SOSManifestCreateWithDigestVector(&dvdels, error);
+    if (ok && additions)
+        ok = *additions = SOSManifestCreateWithDigestVector(&dvadds, error);
+
+    SOSDigestVectorFree(&dvadds);
+    SOSDigestVectorFree(&dvdels);
+
+    return ok;
+}
+
+bool SOSChangeTrackerTrackChanges(SOSChangeTrackerRef ct, SOSEngineRef engine, SOSTransactionRef txn, SOSDataSourceTransactionSource source, SOSDataSourceTransactionPhase phase, CFArrayRef changes, CFErrorRef *error) {
+    bool ok = true;
+    if (changes && CFArrayGetCount(changes)) {
+        CFStringRef changesDesc = SOSChangesCopyDescription(changes);
+        secnotice("tracker", "%@ %s %s changes: %@", ct, phase == kSOSDataSourceTransactionWillCommit ? "will-commit" : phase == kSOSDataSourceTransactionDidCommit ? "did-commit" : "did-rollback", source == kSOSDataSourceSOSTransaction ? "sos" : "api", changesDesc);
+        CFReleaseSafe(changesDesc);
+        if (ct->manifest || ct->manifestChildren) {
+            SOSManifestRef additions = NULL;
+            SOSManifestRef removals = NULL;
+            ok &= SOSChangeTrackerCreateManifestsWithChanges(engine, changes, &removals, &additions, error);
+            if (ok) {
+                if (ct->manifest) {
+                    SOSManifestRef updatedManifest = SOSManifestCreateWithPatch(ct->manifest, removals, additions, error);
+                    if (updatedManifest){
+                        CFTransferRetained(ct->manifest, updatedManifest);
+                    }
+                }
+                if (ct->manifestChildren) {
+                    SOSChangeTrackerUpdatesManifests child;
+                    CFArrayForEachC(ct->manifestChildren, child) {
+                        ok = ok && child(ct, engine, txn, source, phase, removals, additions, error);
+                    }
+                }
+            }
+            CFReleaseSafe(removals);
+            CFReleaseSafe(additions);
+            // TODO: Potentially filter changes to eliminate any changes that were already in our manifest
+            // Backup Peers and the like would probably enjoy this so they don't have to do it themselves.
+        }
+
+        if (ct->changeChildren) {
+            SOSChangeTrackerUpdatesChanges child;
+            CFArrayForEachC(ct->changeChildren, child) {
+                ok = ok && child(ct, engine, txn, source, phase, changes, error);
+            }
+        }
+    }
+    
+    return ok;
+}
+